4wd vs 2wd with locking differential

[Hondo]

Excellent videos about the Eaton G80 Locking Differential-

https://www.youtube.com/watch?v=mk5RAC8qpyo

https://www.youtube.com/watch?v=uLgze5NR6Ks

[Hondo]

A very thorough explanation of all differential types and thier operation-

https://www.youtube.com/watch?v=x40WGUtdaLI

[Mat Mobile]

Great information Hondo! Thanks for sharing!

[Mat Mobile]

I saw this video with great content about the 4WD vs 2WD van debate.

[Davydd]

Originally Posted by Mat Mobile

I saw this video with great content about the 4WD vs 2WD van debate.

Basically they mentioned they didn't get 4WD because of availability and cost and then jumped into the many ways to go off road with 2WD and recover. Their blog and achievements with #vanlife are impressive. Their total cost of converting a Sprinter van bought used was less than $40,000 DIY and they pack a lot of stuff in it and have been to Alaska of all places. They are the young active adventure van couple that the WGO Revel was modeled to go after I would guess.

https://adventureinabackpack.com/diy...an-conversion/

[Hondo]

Davy beat me to it.

While they have rationalized their position, they also take care not to exceed their self imposed limitations as owners of a 2 wheel drive van. Their view is wise but not any different than anyone that takes a 2WD vehicle down dirt roads or through snowy areas.

Where they won't venture is where a more capable vehicle with AWD/4WD will ie: deep snow, desert sand washes, very uneven terrain, steep & loose areas and mud. Having the extra capability will change things for those drivers that really want to get out there.

Also, they have not lifted their van so clearance is also an issue and will limit them to graded dirt roads.

[Mat Mobile]

Originally Posted by Hondo

Also, they have not lifted their van so clearance is also an issue and will limit them to graded dirt roads.

And it's a looong van! I agree that a little 2" lift would do a lot of good on that van.

But their point is also that, despite of not having 4x4, and by being responsible (recovery gear), they were able to get to pretty much everywhere they wanted to go. (I'm not even sure what kind of diff. they have.)

They also mention "Driver ability is more important, in my opinion, than the vehicle capabilities. Knowing how to choose lines, having a good spotter, and being able to back out of a situation are more important than the vehicle you have, so know your own limitations in driving off road." Which is true whether you have a 2x4 or 4x4.

And just in case anybody needs this for future reference, here's their blog post about the same subject: 2WD vs 4×4 Campervan- Considerations and Off Road Recovery Gear.

-----

To me, the debate is pretty simple (not including lifts & tires):

- No locking diff = 0$
- Locking diff installation (in my case) = about $1,000
- 4x4 conversion = about $15,000+

[Deano]

In my experience, with 2 wheel/FWD each of the tires are getting approximately 50% of the power, and the other tires are not trying to rotate, but are being pushed/dragged through mud, sand, snow. The result is, the 2 powered tires are more likely to lose traction.
With 4 wheel drive/AWD, each tire receives approximately 25% of the power. And each tire is trying to rotate, not just being pushed/dragged. Therefore, they are more likely to maintain traction.
The addition of limited slip/lockers center, front, and or rear does not change the above.

[Hondo]

Originally Posted by Deano

In my experience, with 2 wheel/FWD each of the tires are getting approximately 50% of the power, and the other tires are not trying to rotate, but are being pushed/dragged through mud, sand, snow. The result is, the 2 powered tires are more likely to lose traction.
With 4 wheel drive/AWD, each tire receives approximately 25% of the power. And each tire is trying to rotate, not just being pushed/dragged. Therefore, they are more likely to maintain traction.
The addition of limited slip/lockers center, front, and or rear does not change the above.

That is not always the case- watch the Eaton G80 video (with the brown Chevy) for 3 graphic examples.

[BBQ]

Originally Posted by Deano

In my experience, with 2 wheel/FWD each of the tires are getting approximately 50% of the power,....

No 2WD/FWD car ever gives 50% of the power to each wheel.
The differential makes sure of that.

[Deano]

Originally Posted by Hondo

That is not always the case- watch the Eaton G80 video (with the brown Chevy) for 3 graphic examples.

I am NOT saying if traction of a tire is lost, an L/S, locker or traction control does not help. They do in most cases, if the other tire(s) have sufficient traction to handle the addition power.

That does NOT change the basic advantage of 4 wheel/AWD over 2 wheel.

[Deano]

Originally Posted by BBQ

No 2WD/FWD car ever gives 50% of the power to each wheel.
The differential makes sure of that.

If you are moving in a straight line, under light throttle, then what percentage of power is going to each tire?

[booster]

Originally Posted by Deano

If you are moving in a straight line, under light throttle, then what percentage of power is going to each tire?

That depends on a whole multitude of things. The physics and geometry and internal construction of the differential would determine how much force actually got to each wheel, but that is not the point with a locker vs open differential. In reality, the two tires are never rotating at exactly the same speed due to different rolling diameters, The difference may be very small, or quite large, but it is always there. Having different tire sizes will heat up an differential because of the extra rotation in it from the speed mismatch, will lock an autolocker like a Gov-lock if the rpm difference is large enough and speed is low, and will destroy the clutches in a limited slip. Consistent side to side tire rolling diameters is quite important.

The big thing is that even if the force to each side was identical, you could easily still be sitting still with an open axle. All that needs to happen is for that force to be forced low by a tire with low traction, so that the same force on the other tire that does have traction is not enough to move the vehicle. What is important is actually to be able to unbalance the force to each wheel by locking them together as a constant speed device, instead of constant force device, so that any wheel that has traction will receive higher force to use the traction available.

[BillsPaseo]

A helpful little trick for both open and limited slip differentials is to apply the brakes. This adds torque to the spinning wheel so more is transferred to the other. I've used this trick a few times, and it does work, but nowhere near as well as a locker.

[booster]

Originally Posted by BillsPaseo

A helpful little trick for both open and limited slip differentials is to apply the brakes. This adds torque to the spinning wheel so more is transferred to the other. I've used this trick a few times, and it does work, but nowhere near as well as a locker.

Hadn't heard of that trick for years! It does work, especially with drum brakes because they never seem to apply at the same time side to side, and if you get lucky and get the right wheel applying first.....

[roamingcamper]

If you haven't already, go check out the Slow Roamers on YouTube ... they've got lots of discussions about 2wd vs 4wd.

Examples:

https://www.youtube.com/watch?v=jggNhzhE0Cc

https://www.youtube.com/watch?v=KmKry7nul_4

https://www.youtube.com/watch?v=CNE1k8kCkkY

[The Eyesore]

Not gonna lie. The sand video was pretty cool. I learned a lot.